[151545] in North American Network Operators' Group
Re: last mile, regulatory incentives, etc
daemon@ATHENA.MIT.EDU (Jimmy Hess)
Sat Mar 24 00:00:08 2012
In-Reply-To: <4F6BA49C.7040004@necom830.hpcl.titech.ac.jp>
Date: Fri, 23 Mar 2012 22:59:23 -0500
From: Jimmy Hess <mysidia@gmail.com>
To: Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
2012/3/22 Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>:
> William Herrin wrote:
> The entire optics is shared by all the subscribers sharing
> a fiber.
> Thus, the problem is collision avoidance of simultaneous
> transmission, which makes PON time shared with L2 protocols.
Hm... i'm thinking one transceiver might malfunction and get
stuck/frozen in the "transmitting pulse" state, thus making
collision avoidance impossible, kind of like a shorted NIC on a shared
bus topology LAN, if just one subscriber's equipment happens to have
the right kind of failure, and that's neglecting the possibility of
intentional attack.
Passive optically-shared fiber networks don't sound so hot in that case.
>> So, you share fiber by having one guy control one wavelength (color,
>> e.g. red) and another guy control another wavelength (e.g. blue).
> That's not a usual PON but WDN PON.
--
-JH
